1. For testing and learnig purpose you should use one of the already created BPMN 2.0 workflow packed in Alfresco. You recognize them by extension *.bpmn20.xml
2. Install Activiti plugin for Eclpise for editing already mentioned worflows (*.bpmn20) (find some other tutorial)
3. Try one of worflows and edit some values, I choose adhoc.bpmn20.xml like example, make sure that at the end you rename file like adhoc_2.bpmn20) and copy xml file to your alfresco workflow directory (find some other tutorial)
4. Go to alfresco not share. Login as admin and then you go to workflow console
5. into your worflow console type deploy activiti /alfresco/extension/workflow/adhoc_2.bpmn20.xml (type help for more useful commands, you gonna need them), after deploying you might see workflow id and other information about what you are doing…
6. then you have to logout and login again to your share or alfresco and after that go to the list of worflows and you should see it in your list
7. Don't give up.